Method for Changing States of Electrochromic Film

2. The electrochromic device of claim 1, wherein the sensor comprises a spectrometer configured to determine a spectral power distribution of a light intensity over a range of wavelengths.

6. The electrochromic device of claim 1, wherein the controller is configured to inject an amount of electric charges into the electrochromic film or remove an amount of electric charges from the electrochromic film based on the determined color, until a difference between the color and a target color of the electrochromic film is less than a threshold.

8. The electrochromic device of claim 6, wherein the target color is a color of the electrochromic film when the electrochromic film is in (i) a dark or light state and (ii) an undegraded state.

11. The electrochromic device of claim 1, wherein, to inject the amount of electric charges into the electrochromic film or remove the amount of electric charges from the electrochromic film based on the determined color, the controller is configured to apply a DC voltage or DC current to the electrochromic film.

12. The electrochromic device of claim 1, wherein, to inject the amount of electric charges into the electrochromic film or remove the amount of electric charges from the electrochromic film based on the determined color, the controller is configured to apply a pulse voltage or pulse current to the electrochromic film.

15. The electrochromic device of claim 14, wherein the signal receiver is further coupled to the solar cell directly and configured to receive the signal or information of the light intensity.

16. The electrochromic device of claim 14, further comprising a power output control configured to receive power indirectly from the solar cell and supply power to the electrochromic film.

17. The electrochromic device of claim 16, wherein the power output controller is configured to inject an amount of electric charges into the electrochromic film or remove an amount of electric charges from the electrochromic film.

18. The electrochromic device of claim 17, wherein, to inject the amount of electric charges into the electrochromic film or remove the amount of electric charges from the electrochromic film, the power output controller is configured to apply a DC voltage or DC current to the electrochromic film.

19. The electrochromic device of claim 17, wherein, to inject the amount of electric charges into the electrochromic film or remove the amount of electric charges from the electrochromic film, the power output controller is configured to apply a pulse voltage or pulse current to the electrochromic film.